Compressor



' Fb. 10, 1959 E. KODRA I 2,873,061

COMPRESSOR File d Oct. 13. 1953 6 Sheets-Sheet 1 F|G.1. v no mvsmon: ESPER KODRA ATTORNEY E. KODRA Feb. 10, 1959 COMPRESSOR 6 Sheets-Sheet 2 Filed Oct, 13, 1953 94 INVENTORZ ESPER KODRA BY $37M ATTORNEY Feb. 10, 1959 E. KODRA 2,87

' COMPRESSOR Filed 001;. 15, 1953 6 Sheets-Sheet 5 FIG. 3.

mvem'om ESPER KODRA ATTORNEY 1959 E. KODRA 7 2,873,061

COMPRESSOR Filed Oct. 15, 1955 6 Sheets-Sheet 4 NNNNNNN R ESP ER KODRA biw TTTTTT EY Feb. 101-1959 Filed Oct. 13, 1953 E. KODRA COMPRESSOR 6 Sheets-Sheet 5 lllll TQR: PER KODRA ATTORNEY Feb. 10, 1959 E, Ko-DRA 2,873,061

COMPRESSOR 7 Filed Oct. 13, 1953 v s Sheets-Sheet 6 FIG. 12. i

229 1 I 1 \h I I Q g k INVENTOR; ESPER KODRA ATTORNEY United States Patent COMPRESSOR Esper Ko'dra, Michigan City, 11111., assignor to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application October 13, 1953, Serial No. 385,833

3Claims. (Cl.230--212) This invention relates to a compressor, and particularly to a compressor which compresses a gaseous substance that must not be contaminated with combustible lubricents, such as hydrocarbons.

There are numerous industrial applications in which gases ,or mixtures of gases must be kept free of combustible substances. An example is oxygen, either pure or nearly pure. Oxygen with small amounts of hydrocarbons forms a readily explosive mixture which, if detonated, can result in heavy loss of life and destruction of property. Other examples will be apparent to those skilled in the art.

It is accordingly an objectof this invention to provide a gascompressor which compresses the gas in a chamber to which no fluid lubricants are admitted. This and other objects are accomplished in a compressor in which the compression space ,is atleast partially bounded by .a non-metallic liner, a piston .being'reciprocable in the non- Inctallic liner and being provided, outside the compres- Sion vSpace, with sealing members having a very low coelficient of friction, the sealing members being spaced apart and alternating with cooled spacer members. In a preferred embodiment of the invention, the piston and the non-metallic liner for the compression chamber are also artificially cooled.

In the drawings:

Fig. 1 is .a yiew in elevation of a compressor made according to the invention;

Fig. ,2 is an enlarged detail view of the compressor cylinder, being taken from the same view point as Fig. l but with parts broken away and in section;

Fig.3 is a viewin section on line 3-3 of Fig. 2;

.Fig. 4is a view in section on line 4-.4 of Fig. 3;

Fig. 5 is aview in section on line 5-5 of Fig. 3.;

Fig. 6 is a .view in sectionon line 6-6 of Fig. 3;

, ,Fig. 7is a view in section on line 7--7 of Fig, 5;

Y Fig. .8 is a view insectionon line 8-8 of Fig. 5;

,Fig. 9is ,a view in section on line 9-9 of Fig. ,3;

.Fig- 10 ;is a view insection on line 1tl--10 of Fig. 9;

Fig. 11 is aviewinsection on line 11-.-11 of Fig. 9;

Fig. 12 is a sectional view similar to Fig. 3 but showing another embodiment of the invention;

QFig. 13 is a schematic diagram of the cooling circuit for ,the packing of the embodiment shown'in Figs. 1-l1; and

,Fig. 14 vis a schematic diagram of the cooling circuit of'the embodiment of the invention shown in Fig. 12.

Referring ,now in detail to the embodiment of the inventionshown in Figs. l-ll, a machine made according to ,this invention is provided with a pedestal 2. Pedestal 2,,serves as a crankcase having access openings which are normally closed by covers 4. ,Anflywheel 6 is secured to one end of the crankshaft. The lubrication system forthe chassisis indicated generally at 8 and need not be detailed because lubrication systems of this type are well understood by those skilled in the art.

.A machine made according to this invention is preferably provided with suitable gages, such as inlet pres- 2,873,061 Patented Feb. 10, 1959 2 sure gage 10, xdischargepressure gage 12, and oil pres? sure gage 14. Gas inlet line 16goes to an inlet surge chamber 18.

The compression chamber and associated mechanism are supported at the upper end of pedestal 2 by a distance piece 20. Reference will be had particularly to Fig. 3 for most of the pertinent details. As there shown, the compression space is bounded at least in part by anonmetallic member 22, member 22 being a carbon sleeve or liner for the cylinder 24. Cylinder 24 is provided with cooling means consisting of a helically arranged passage 26. Passage 26 is provided with an inlet connection 30 and a discharge connection 32. The cooling water inlet and discharge connections need not necessarily be arranged precisely as shown, but may be arranged where desired.

A piston 34 is mounted for reciprocation in the liner 22. As will be understod by those skilled in the art, piston 34 will be connected to the crankshaft (not shown for reciprocation through a working stroke which is less than the axial length of liner 22. In order to provide a substantial seal against gas leakage, piston 34 is made several times the length of stroke or, what isnearly the same thing, the length of the cylinder. Thus, piston 34 is roughly four times as long as the stroke through which the piston reciprocates, and from four to five times as long as the cylinder or cylinder liner in which the upper end of the piston reciprocates.

Piston 34 is conveniently fabricated or built upof a number of elements. Thus, a shell 36 is counterbored at its upper end to receive an end plug 38 which is desirably welded in place as shown at 46. At its lower end, shell 36 is similarly counter-bored and welded to an endpiece 42 as seen at 44. A clamping plate 46 is secured to the endpiece by suitable threaded members 48. Endpiece 42 is recessed :to receive the enlarged end 50 .of a connecting rod 52.

End plug 33 is recessed as shown at 54 to provide a deflecting surface for cooling water. Endpiece 42 is suitably bored as will be detailed later to direct cooling water flow, and is centrally bored as shown at .56 to permit the passage of cooling water. Bore 56 isenlarged to receive one end of acooling water tube58, the other end .of which is held in place by a centering member 60. As is best seen in Fig. 6, centering member 60 is provided with ,a cylindrical outside diameter which engages the inside diameter of shell .36 and. is provided with a plurality of spaced arcuate recesses 62 about its periphery in order to permit the passage of cooling water. A sleeve 64 secured to centering member 60 and endpiece 42 keeps the cooling water tube 58 out of thermal contact with the cooling water which is immediately adjacent the inside .of shell 36. The annular space 66 between the cooling water tube 58 and the cooling water sleeve 64 is vented to the crankcase by means of intersecting passages 68 and 70 in the endpiece 42; see especially Fig. 8.

A substantially radial passage 72 communicates with passage 56 and is tapped as shown at 74 to receive a cooling water fitting 76; see particularly Figs. 2, 5 and 7. The annular cooling water passage between sleeve 64 and shell 36 connects with passages 78, 80 and 82, passage 82 being tapped at 84 to receive a fitting 86.

the hoses.

here shown as being provided with slots196 through which the flexible hoses extend and in which the Stationary fittings 88 and 90 are mounted.

In order to keep the moving fittings 76 and 86 alined with the slots 96, and thus to prevent fouling of the flexible lines 92 and 94, the endpiece 42 is tapped as shown at 98 to receive a cooperating threaded member 100 which carries a roller 102. Roller 102 moves between guides, one of which is shown at 104 of Fig. 3, suitably secured inside the distance piece 20.

Distance piece 20 is drilled and tapped at suitable intervals, as shown for example at 106. Studs 108 are threaded at one end to cooperate with the tapped holes 106, and at their other end (upper end as seen in Fig. 3) are threaded to receive nuts 110. The upper ends of the studs 108 engage a cylinder head assembly 112. Cylinder head assembly 112 is provided with inlet and discharge valves 114 and 116 respectively. The details of these valves form no part of this invention; any of a number of commercially available valves may be used. The valves here shown are of the general type disclosed and claimed in Patent 2,213,259, Paget, assigned to the assignee of this invention.

Between the upper end of distance piece 20 and the cylinder head assembly 112 referred to above, there are disposed the cylinder and the cooled packing referred to generally above. The cooled packing comprises a plurality of spaced annular sealing units surrounding the piston outside the compression space, a plurality of spaced members separating the sealing units and alternating with them, and means to cool the spaced members.

More specifically, the spaced annular sealing units, sometimes referred to as packing ring units, consist in the illustrated embodiments of the invention of pairs of packing rings 118. The packing rings 118 are of a segmental type, and are arranged in pairs in order that the joints of one ring may fall midway between the joints of the ring with which it is paired. Pins 120 are used to maintain this orientation of the rings relative to each other. Garter springs 121 are used to give the rings a continuing bias radially into sealing contact with the surface of the piston.

' course suitably pinned in the same manner as adjacent The spaced members which separate the sealing units are sometimes referred to as cooling rings, and are shown at 122. The rings forming the sealing units are preferably made of a substance having a low coeflicient of friction, preferably carbon, and are in close contact with the piston. The alternating cooling rings 122 are of a material having a high heat conductivity, preferably metal, and are not in contact with the piston, although they are in thermal contact with their adjacent sealing units.

Cooling rings 122 are very carefully machined. The distance L (see Fig. 10) between the plane surfaces 124 and 126 is very carefully maintained in order to avoid pinching the sealing units 118 between adjacent cooling rings, and to permit them freedom to move radially in ward as wear progresses.

Cooling rings 122 are preferably made in two parts, in order that annular flow passages 128 may readily be machined in them. By' flow passages 128, I here mean the complete flow passage formed by the two cooperating parts of the cooling ring. The ring is further provided with connecting passages 130 and 132. Axial flow passages 134 are provided in the rings, and connect the passages 130 of the several rings with additional axial passages 136 of the cooperating adjacent rings, passages 136 being provided in communication with the passages 132.

In order that the two parts of any given ring may maintain a correct orientation relative to each other, the two parts are suitably drilled and provided with pins 138 (Fig. 9 and 11). After fabrication, the two parts of a ring are permanently secured together in any suitable manner as for example by silver soldering.

' In order that a given complete cooling ring 122 may cooling rings in order to maintain the proper alinement of the passages 136 and 142.

Axial passage 142 intersects with a passage 144 in the cylinder 24, passage 144 being tapped to receive asuitable connection 146 (Fig. 2). At the other end of the cooling passage for the cooling rings, the lower end cooling ring 122' is similarly provided with a tapped opening 148. A suitable fitting 150 (Fig. 2) is provided in the opening 148.

As is best seen in Fig. 2, distance piece 20 is suitably drilled and tapped for the external cooling water connections. Thus, a tapped hole 152 may be used to provide the cooling water inlet, and communicates with an intersecting passage 154, in which there is provided a fitting 156 from Which a conduit branches and is connected to the fitting 150 referred to above. Fitting 156 is connected with fitting 30 by a conduit 160 and suitable cooperating fittings. The fitting 146 referred to above is connected with a conduit 162 which connects with another conduit 164. Conduit 164 is connected at its one end with fitting 32, and at its other end with suitable intersecting passages 166 and 168 in the distance piece 20. The various plumbing details are not set forth here because they are entirely conventional and form no part of the invention per se. A suitable fitting engages the tapped opening 168 in distance piece 20 and may provide the cooling water discharge.

The flow of cooling water indicated in the above description and by means of arrows on the accompanying drawings is intended to be illustrative. It may well be found in some applications of the invention that the directions of fiow should be reversed, or that other connections than those shown will more expeditiously cool the compressor.

Distance piece 20 is provided with an inward extending flange 170 (Fig. 2) of which the upper face is counterbored to receive the flange 172 of a packing member 174. Flange 172 of the packing member 174 cooperates with the lowermost cooling ring 122', to the end that the entire assembly of cooling rings and compressor cylinder are clamped between the internal flange 170 of distance piece 20 and the cylinder head assembly 112 by means of the several studs or bolts 108.

Packing member 174 is provided with any suitable conventional packing 176. Packing member 174 is recessed as shown at 178, and the chamber thus provided adjacent the cooling ring 122 is drilled as shown at and is tapped at 182 in order to permit connection of the drilled passage 180 with any suitable gas space by means of a conduit 184. Where the gas being compressed is a valuable or noxious gas, conduit 184 may be connected back to a reservoir (if the gas is valuable) or maybe otherwise suitably disposed of if the gas should happen to be a noxious gas. If neither of these conditions obtains, conduit 184 may of course simply communicate with the atmosphere.

Reference is now made to the embodiment of the invention shown in Fig. 12. In order to avoid duplicationv of description, the discussion of the embodiment shown in Fig. 12 will be limited to a discussion of the major differences between the two embodiments of the'invention.

One major difference between the two embodiments is the construction of the cooling rings. In the embodiment shown in Figs. 1-11, the correct spacing between cooling rings is provided by a cylindrical extension which is integral with the cooling rings; see the above discussion of? the. distance L. (Fig. and; the cooperating; 8.11.1. aQSt12 fifi 1.2.6... lathe. embo iment-shown iii-P a 12 the correc z pacinahe we n eblins ingslzz is; provid d it-means of: s parate. istance rings. 2.2.3,. The flew Pas.- sages. 2125 may e... andp e era y are. pr i ed n. the same manner as in the first embodiment, namely by forming the cooling rings of two parts and silver soldering the two parts together.

Another major difference between the two embodiments that strikes the eye is the difierence in the valves. Whereas the embodiment shown in Figs. 1-11 uses inlet and discharge valves which are separate assemblies, the valve assembly indicated generally at 229 of Fig. 12 illustrates valves of the coaxial type. Valves of this type have been commercially available for many years, and their details need not be set forth here.

Operation In this discussion of the operation, reference will be to the embodiment shown in Figs. 1-11 unless otherwise indicated. Piston 34 is reciprocated through its given stroke by means of power applied to the compressor through the flywheel 6 which serves as a pulley, and through the associated crankshaft and connecting rod (not shown), and the piston rod 52. Piston 34 is maintained in its proper orientation by the roller 102 reciprocating between its constraining guides, one of which is shown at 104 in Fig. 3.

Piston 34 reciprocates through its given stroke in the carbon liner 22 of cylinder 24. The piston stroke is of course somewhat less than the axial dimension of the carbon liner 22. The gas to be compressed enters the compression chamber through inlet valve 114 and is discharged by way of discharge valve 116. Gas which leaks past the packing units consisting of the several pairs of rings 118 is collected in the annular recess 178 (Fig. 2) and is conducted away by means of passage 180 and conduit 1S4.

Piston 34 is cooled by means of cooling water admitted through the connection 88, flexible hose or conduit 92, fitting 76, tapped hole 74, passages 56, and tube 58. Tube 58 conducts the cooling water to the upper end of the piston, namely to the recess 54, whence the cooling water flows downward through recesses 62, the annular passage between the sleeve 64 and the shell 36, passages 78, 80 and 82, fitting 86, flexible hose 94, and fitting or connection 90. Heat of friction and compression is of course absorbed by the cooling water in its flow through the piston as outlined above.

Outside the compression chamber, sealing rings 118 disposed in pairs or units maintain a tight sliding contact with the highly finished surface of piston 34. The garter springs 121 keep the rings 118 in close engagement with the piston surface. Heat generated in the sealing units is abstracted by means of the cooling rings 122.

Cooling rings 122 are cooled by the flow of cooling water through the several passages 136, 134, 130, 128, 132, 136 etc. Cooling water is supplied to the rings at the lower end of the assembly by conduit 158 and fitting 150, and is taken from the assembly by means of fitting 146 and conduit 162.

At the same time, cooling water circulates through the embedded coil 26 in cylinder 24 and serves to cool the carbon liner 22. Cooling water is supplied to cylinder 24 from conduit 160 through fitting 30, and leaves by way of fitting 32 and conduit 164.

One manner of connecting the cooling passages 128 is shown schematically in Fig. 13. It is readily seen from that figure that the cooling water flows through the several passages 128 in series. It will readily be understood by those skilled in the art that the scheme shown in Fig. 14 for the embodiment of Fig. 12 may be used if desired. In the system shown schematically in Fig. 14,

cooling water flows. thr gh e, several. cooling rings 228 in parallelinsteadof in series.

It will be apparent to those skilled in the art that I have here provided. a. novel. type. of compressor which can: beused to. compress. gases; without. the danger of contaminating those gases with lubricants and which is designed for a maximum life of the non-metallic, low friction, materials used in the construction thereof.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

I claim:

1. For use in cooling and packing of an elongated reciprocating cylindrical member, a plurality of annular elements arranged side by side and each having a groove therein extending outwardly from its inner periphery for receiving a sealing unit therein, each of said annular elements having a circumferential passage, at least a pair of connecting passages connected to said circumferential passage, one of said pair of connecting passages including an inlet portion and the other of said pair of connecting passages including an outlet portion, said inlet portion of one of said annular elements communicating with the outlet portion of the next preceding annular element and said outlet portion of said one annular element communicating with said inlet portion of the next successive annular element whereby coolant can flow progressively through said passages of the various annular elements.

2. In a compressor, in combination, a cylinder having a compression space, a piston reciprocable in said cylinder, a plurality of annular elements arranged side by side and each having a groove therein extending outwardly from its inner periphery for receiving a sealing unit therein, said sealing units surrounding said piston and being in contact therewith, each of said annular elements having a circumferential passage, at least a pair of connecting passages connected to said circumferential passage, one of said pair of connecting passages including an inlet portion and the other of said pair of connecting passages including an outlet portion, said inlet portion of one of said annular elements communicating with the outlet portion of the next preceding annular element and said outlet portion of said one annular element communicating with said inlet portion of the next successive annular element whereby coolant can flow progressively through said passages of the various annular elements.

3. A compressor having a compression space bounded at least in part by a non-metallic member, means to cool the non-metallic member, a piston reciprocable through a given stroke in said compression space, a plurality of annular elements arranged side by side and each having a groove therein extending outwardly from its inner periphery for receiving a sealing unit therein, said sealing units surrounding said piston and being in contact therewith, each of said annular elements having a circumferential passage, at least a pair of connecting passages connected to said circumferential passage, one of said pair of connecting passages including an inlet portion and the other of said pair of connecting passages including an outlet portion, said inlet portion of one of said annular elements communicating with the outlet portion of the next preceding annular element and said outlet portion of said one annular element communicating with said inlet portion of the next successive annular element whereby coolant can flow progressively through said passages of the various annular elements.

(References on following page) References Cited in the file of this patent 1,879,370 1,933,678

UNITED STATES PATENTS 2,204,374

730,925 Klein June 16, 1903 2 292 617 1,462,855 Gerleman July 24, 1923 5 2,439,957

8 McAllister Sept. 27, 1932 Morterud Nov. 7, 1933 Metzgar June 11, 1940 Dana Aug. 11, 1942 Anderson Apr. 20, 1948 

